1. Field of the Invention
The present invention is directed to fastener driving devices, and more specifically relates to fastener driving devices that incorporate mechanisms for limiting the movement of nails.
2. Description of Related Art
The construction industry has seen an increase in the use of metal connectors when joining two workpieces together. For example, joist hangers are commonly used in the construction of floors in buildings and outdoor decks. L-shaped metal connectors are also used to connect and/or reinforce two workpieces that are joined together perpendicularly, such as when connecting the framing of two walls. Conventional fastener driving devices, such as pneumatic nailers, have been difficult to use in metal connector applications because of the size of such devices. For example, a conventional pneumatic nailer used for framing applications is designed to drive nails that are 2 to 4 inches in length and have diameters of about 0.113 to 0.162 inches. However, nails that are used to attach metal connectors to workpieces are typically about 1.5 to 2.5 inches in length, and have diameters of about 0.131 to 0.162 inches. While framing nailers may be used to drive the longer metal connector fasteners as well as shorter metal connector fasteners, they are typically not optimally configured to drive shorter metal connector fasteners such as nails that are 1.5 inches in length.
Moreover, the design of conventional pneumatic nailers makes it difficult to accurately locate a fastener into the hole of the metal connector due to the nose assembly and the contact arm. A conventional contact arm is biased to extend past the nose assembly of the nailer so that when the contact arm is pressed against the workpiece, the contact arm cooperates with the trigger to cause the nailer to actuate, and drive the fastener into the workpiece. In many applications, such as framing and finishing, the fastener may be located in a range of locations, i.e. the precise location of the fastener may not be important. However, when driving a nail through a hole of a metal connector, the precision of the drive is important because of the risk of damaging the nailer or the metal connector. In this regard, various conventional fastener driving devices are now being configured to allow use of special removable probes that aid in locating of the holes in the metal connectors.
Users have used the tip of the fastener that protrudes from the nose assembly which is about to be driven as the hole locator. In particular, the nails slightly protruding from the nose assembly of the nail gun are used to locate the hole of the metal connector by sliding the nail tip along the metal connector until it falls into the hole of the metal connector. Then, the nail is driven into the workpiece thereby securing the metal connector to the workpiece. However, such use of the tip of the fastener as a hole locator poses specific problems.
More specifically, when the tip of the nail locates the hole of the metal connector and digs into the workpiece through the hole, the nail tends to slide back into the magazine which may cause the head of the nail to be slightly misaligned with the driver of the fastener tool. This potential for misalignment is increased by the fact that most conventional pneumatic tools require the user to push on the tool downwardly against the workpiece to engage the safety mechanism, and to allow the tool to fire. Such pushing of the tool can also cause the nails to recede further into the nose assembly of the fastener driving device, thereby further increasing the potential for misalignment.
Moreover, the collation material such as paper, plastic, or metal strips that interconnect the nails together can accumulate in the drive channel of the nose of the fastener driving tool, and resist proper feeding of the next nail that is to be driven. Of course, such accumulation of the collation material can also cause misalignment. All of these factors that increase likelihood of misalignment can increase the frequency of tool jamming or blank firing in which no nail is driven.
Furthermore, as noted above, common nails for metal connectors are 2.5 inches and 1.5 inches, depending on the particular requirements of the specific application. Thus, two different sized nailers are required in order to drive these different sized nails, thereby adding to tool costs.
Therefore, there exists an unfulfilled need for a fastener driving device that more accurately controls the movement of nails as compared to conventional fastener driving devices. In addition, there also exists an unfulfilled need for such a fastener driving device that controls the movement of different sized nails that are driven by the fastener driving device.